The search continues for survivors of a ferry accident off the southwestern tip of South Korea. So far, there have been at least 25 confirmed deaths, close to 300 people are still unaccounted for. Most of the missing are high school students who were headed toward the island of Jeju on a class trip. After a full day of searching, both on the surface and with hundreds of divers under water, there were no additional rescues.

Earlier, I spoke with NPR's Anthony Kuhn, who is in the seaside town of Jindo. He described the scene there following the rescue operation.

ANTHONY KUHN, BYLINE: I was standing on the seashore where they send the search ships out and they bring back the survivors. And there was just a feeling of exasperation among the family members. They were saying, you know, what are these searchers doing that they're not finding any survivors? They're not searching hard enough. And when the prime minister went to the gymnasium, where a lot of these families were waiting, they pelted him with water bottles. They blamed him for not searching hard enough.

When the president, Park Geun-hye, went to that gymnasium, a young girl knelt down on the ground in front of her and implored her to do something. And her remark was that as long as there is hope of finding survivors, every second counts. So the anger and frustration today was really palpable, both at the seashore and at the gymnasium where families were waiting.

CORNISH: Anthony, what is known at this point about why the ship capsized?

KUHN: So many theories have come out about why it capsized. The first was that it hit something and there was a sound that many people interpreted to be hitting a rock or something underwater. Also, a lot of people are talking about why it capsized so quickly. This is a large ferry carrying shipping containers, carrying quite a lot of vehicles; people wonder if, you know, once that heavy cargo was dislodged it could cause the thing to capsized quickly.

There's also speculation that it took a quick turn, that it veered off course, turned sharply and caused the thing to capsized. But because it capsized, people were not able to exit their cabins below the deck and they were trapped underwater.

CORNISH: Anthony, can you just give us an update on the rescue effort itself. What are some of the difficulties there in terms of getting to people?

KUHN: Well, the ferry went down in a part of the Yellow Sea which is pretty turbulent at this time of year. It's been raining two days straight, very strong winds and high waves. The water in that part of the Yellow Sea is very silty and so visibility is very poor for the divers. And the currents are very strong. It's very hard for them just to stay in one place so they can get inside the ship.

They wanted to try to pump air inside the ship today, to try to give something for possible survivors to breathe. But it was postponed because of the difficulty. So they've had just two days of really difficult weather to deal with. And as angry as the parents are, it's somewhat understandable that they're having these difficulties, considering the circumstances.

CORNISH: That's NPR's Anthony Kuhn on the South Korean island of Jindo. Anthony, thanks so much.